Improvement in piston-packings



YU'Nrrnn l'S'rrrrns PATENT n FFICE.

JAMEs McALoNAN, on NEw YORK, N. Y.

IMPROVEMENT IN PISTON-PACKINGS.

. Specification forming part of Letters Patent N 0. 116,336, dated June-27, 1871.

To all uhom itymag/ concern:

Be it known that I, 'J AMES' MCALONAN, of the city, county, and State ofNew York, have invented a new vand Improved Piston -Packingg and I dohereby declare th'at the following is a full, clear, and exactdescription thereof, which will enable others skilled in the art to makeand use the same, reference being had to the accompanying drawingforming part of this specification, in which- Figure l represents alongitudinal central section of a piston provided with my improvedpacking, the plane of section beingindicated by the linea' x, Fig. 2.Fig. 2 is a transverse section of the same on the line y y, Fig. 1. Fig.3 is a detail central section ofone ofthe inner rings. Fig. 4 is anouter, and Fig. 5 an inner-face v iew of one of the Lexpandingspring-plates.

Similar letters of reference indicate corresponding-parts.

My invention consists in the improvements upon piston-packin g, whichare hereinafter fully described and subsequently pointed'out in theclaims.

Ain the drawin g represents a tubular pistonrod, of suitablelength anddiameter. To it are secured the heads or end plates B C of the piston,both of equal diameters. The end of the tube receiving-the plates .B Cis made conical,

- as shown in Fig. 1, the central apertures of thev plates beingtapering to fit it, Vand a nut, a., screwing` upon the extremity of thepiston-rod, crowding them home. The plate B has a projecting centralblock or core, b, which reaches to the other plate C, so as to determinethe distance between the same, besides forming a support for theexpanding pins. Through the piston-rod is tted a small bar, D, whichcarries a conical plug, c, in line with the-core b. Through the core arefitted three or more transverse pins E E, which can be moved outwardlytoward the periphery of the piston by pulling the bar D.

The outer end of the bar D projects beyond the piston-rod, andreceives anut, d, whereby itl can be longitudinally adjusted in the pistonr-f-rod.

The nut d' has a tubular extension, c, which is closed by a screw-cap,f. rlhe pins E E extend with their/outer ends against the expandingspring-plates F F. The ends of each springplate F are V-shaped, ordouble inclined, as in Figs. 4 and 5, and t into recesses which areprovided intwo split rings, G- G, that are set one upon the other,between the plates B (l. These recesses g in the rings G are cutslanting, as shown in Fig. 1, so that whenever the-plates F are pushedoutwardly by the pins E they will not only expand the rings G, but alsocrowd them against t-he plates B C to let the joints be absolutelytight. The rings G G are close within the outer piston-rings H and I.The latter are triangular in their cross-sections, and put together sothat the long sides of the triangles comen contact, as is clearly shownin Fig. l.

Whenever the piston leaks, the cap f is unscrewed andthe nut d turned soas to pull the core c, and thereby expand the pins E. The pins crowdagainst the rings G so as to spread them, and with them the rings H I,until the outermost ring I fits the cylinder properly. The lengthwiseextension of the two rings G G shared by the rings H I, which slide inthe inclined surface between them so as to crowd against the plates B C.As the pins E do not work steam-tight in the core b, the steam, if itenters the piston, will also pass into the tube A and betray animperfect iit by its escape when the cap f is removed. The proper iit ofthe piston can thus always be ascertained without removing thecylinderhead, and connected by merely turning the nut d. A plug', h, isscrewed into the inner end ofthe tube A to keep it closed, or anequivalent stop is applied.

Having thus described my invention, I claim as new and desire to'secureby Letters Patent- 1. The spring-plates F F, provided withdoubleinclined ends, whereby they crowd the rings G G apart whileexpanding them, as specified.

2. The double rings G G, provided with the inclined recesses g, tobemoved apart while expanded, as set forth.

3. The nut cl, provided with the tubular extension c and with the'screw-cap j', to regulate the sliding bar D, substantially in themanner specifred. l

. JAMES MCALONAN.

Witnesses:

JOHN MoALoNAN, GEO. -W. MABEE.

